Boring apparatus with valveless impactor



y 1969 H. G. WARRINGTON ETAL 3,444,937

BORING APPARATUS WITH VALVELEISS IMPACTOR Filed June '7, 1967 FIG!INVENTORS' HENRY G. WARRINGTON GEORGE C. MANNING yew United StatesPatent 3,444,937 BORING APPARATUS WITH VALVELESS IMPACTOR Henry G.Warrington, Palm Beach, and George C. Manning, Riviera Beach, Fla.,assiguors to Vulcan Iron Works Inc., Chattanooga, Tenn., a corporationof Illinois Filed June 7, 1967, Ser. No. 644,395 Int. Cl. E21b 1/06,5/00 U.S. Cl. 175-92 8 Claims ABSTRACT OF THE DISCLOSURE The presentinvention relates to a method and apparatus for drilling or boring; andparticularly for boring into rock or other frangible material commonlyfound in the earth.

An object of the present invention is to provide a new and improvedboring apparatus combining the attributes of percussion boring androtary boring.

Another object of the present invention is to provide a new and improvedboring device for use in a borehole. Another object of the presentinvention is to provide a new and improved apparatus for boring intorock or other frangible material commonly found in the earth.

Yet another object of the present invention is the provision of a newand improved method of boring into rock or other frangible materialcommonly found in the earth. Further objects and advantages of thepresent invention will become apparent as the following descriptionproceeds and the features of novelty which characterize the inventionwill be pointed out with particularity in the claims annexed to andforming a part of this specification.

In accordance with these and many other objects of the presentinvention, there is provided an improved boring device for drilling orboring into rock or other frangible material and including a drill headfor carrying suitable cutter bits and having a portion defining animpact pintle. A fluid actuated impactor is positioned to impartpercussion impacts on the pintle while the drill head is simultaneouslyrotated. Thus the invention combines the attributes of percussiondrilling as well as those of rotary drilling.

The invention also relates to a new and improved method of boring ordrilling into rock or other frangible material and including the stepsof rotating a drill head carrying a plurality of cutter bits in aborehole and simultaneously imparting percussion impacts to the drillhead.

For a better understanding of the present invention reference may be hadto the accompanying drawings wherein:

FIG. 1 is a cross sectional view of an improved boring device in itsoperative position in a borehole; and

FIG. 2 is a fragmentary cross sectional view of the boring device ofFIG. 1 illustrated with the ram of the impactor in a different operativeposition.

Referring now to the drawings there is illustrated an improved drillingor boring device 10 according to the present invention and positionedwithin a driven pile 11 in the earth 12. The drilling or boring takesplace beyond the lower open end 11a of the pile 11.

To provide for the drilling and impact, there is provided a drillinghead 15 having a stepped lower surface 150. Conventional cutter rollerbits 16 are radially located on the steps of the drilling head. Internalpassages 17 in the drilling head 15 serve to supply lubricant such asbentonite to the roller bits 16 as they rotate. Additionally thehentonite provides a sealant to enter any interstices which may occur orwhich are existent in the walls of the hole being drilled. The upper endof the drill head 15 defines an impact pintle 18 for receivingpercussion blows.

To provide the percussion blows to the drill head 15 there is providedan impactor 20 including a housing 21 defining a cylinder and having animpact ram or piston 22. The impactor 20 may be of known design and, inthe illustrated embodiment, is of the valveless type having the singlemoving part forming the ram 22. The ram 22 is a differential diametermember having a lower ram portion 22a and an upper piston portion 22b oflarger diameter. Motive fluid such as steam or compressed air entersthrough a fluid inlet 23 into a fluid chamber 24 acting on the area ofthe piston differential to the diameters of the ram portion 22a and thepiston portion 22b to drive the ram 22 upwardly, as viewed in FIG. 1.The upward movement of the ram 22 uncovers a transfer port 24 in thewall of the cylinder communicating to a transfer passage 25 into achamber 26 defined between the ram 22 and the cylinder head 27. Theupward travel of the ram 22 is also effective to close an exhaust port28 from the chamber 26.

From the above description, the operation of the impactor is believedclear. However, briefly, the impactor is of known type wherein the fluidpressure acting on the differential area between the ram portion 22a andpiston portion 22b will drive the ram 22 upwardly from the positionillustrated in FIG. 1 to the position illustrated in FIG. 2. Initialupward movement of the ram 22 will close the exhaust port 28 and openthe transfer port 24 so that pressurized fluid may now enter through thetransfer passageway 25 into the chamber 26 above the piston portion 22b.Since the area of the piston portion 22b opening into the chamber 26 ismuch greater than the differential area between the piston portion 22band the ram portion 22a, the buildup of fluid pressure in the chamber 26will drive the ram 22 downwardly to provide a percussion impact againstthe impact pintle 18 of the drill head 15. Downward movement of thepiston portion 22b is effective to open the exhaust port 28 and torecycle the tool.

The impactor 20 is vertically attached to the drilling head 15 bymechanical means such as a plurality of drill head bolts 30 andcushioned therefrom by a spacer 31 of urethane or other suitablematerial defining a cushion pad of resilient material.

Rotational movement can then be transmitted to the drill head 15 throughthe casing 21 of the impactor 20 by means of a drive or square Kelly bar35. A pressure fluid conduit 36 extends through the inside of the Kellybar 35 and is connected to the fluid inlet 23 ofthe impactor 20.Additionally a conduit 37 extends through the inside of the Kelly barconnected to supply the bentonite drilling fluid to the passageways 17in the drill head 15. The hollow interior of the Kelly bar also servesas an exhaust for the spent motive fluid coming from the port 28. Thepressure and drilling fluids are rotatably admitted to the conduits 36and 37 at the top of the Kelly bar in a known manner by means of atiered pair of swivels. A conduit 38 also exhausts into the hollowinterior of the Kelly bar to provide air relief to the impactor ram 22.

The entire drilling machine assembly is contained within a cylindricalsleeve 40 interposed between the drilling head 15 and a head cap 41. Theentire assembly is held 3 together in the vertical by a plurality ofradially placed post-tensioned cables 42 attached to the drilling headand passing through and secured to the head cap 41.

Advantageously the present invention combines the attributes ofpercussion drilling as well as those of rotary drilling. The drillingoperation may be performed as a dry hole operation or submerged inwater. This type of drilling machine permits drilling beyond thelimiting duct of the pile, caisson or sleeve. The impactive speed androtational speed are independently variable and not coupled or dependentone upon another. A valveless type of impactor has only a single movingpart. The control of the impactor is accomplished by change in themotive fluid pressure. The cable method of assembly provides quickdisassembly and access to the impactor for service. The ingress ofdrilling fluid above the drilling machine provides suspended egress ofthe drilling waste and places the material available for airliftremoval.

A specific embodiment of the invention was designed and specified tooperate on compressed air having a delivery of temperature of 400 F.thus inducing a thermosetting reaction in the bentonite drilling fluidto force closure and sealing of the walls of the hole so drilled.Moreover thermo-set bentonite drilling fluid sealing and lining the holeso drilled is acceptable as form material for concrete poured thereinafter the hole has been drilled.

By its nature and concept, there is no theoretical limit to thediametric size of the holes to be bored. The hole size may be increasedin diameter merely by changing the drilling head.

The present invention also relates to an improved method of boring ahole into rock or other frangible material found in the earth. Morespecifically the improved method includes rotating a drill head carryinga plurality of radially disposed cutter bits, and simultaneouslyapplying percussion impacts to the drill head so as to obtain thecombined attributes of percussion drilling as well as those of rotarydrilling.

Although the present invention has been described by reference to only asingle embodiment thereof, it will be apparent that numerous othermodifications and embodiments will be devised by those skilled in theart which will fall within the true spirit and scope of the presentinvention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. An improved boring device for use in a borehole comprising:

a rotary drill head having a portion defining an impact pintle andadapted to carry a plurality of cutter bits;

a valveless type impactor for imparting percussion impacts on saidimpact pintle including:

a housing defining a differential diameter cylinder closed at the top,

a differential diameter ram reciprocally positioned in said cylinderincluding an upper piston portion and a lower ram portion of reduceddiameter,

inlet means for introducing fluid under pressure between the twoportions of said piston,

exhaust means for said closed end of said cylinder including a portopening into the cylinder side wall positioned to be closed when saidpiston moves upwardly, and

fluid passage means communicating with the closed end of said cylinderand including a port in the side wall of said cylinder positioned to beopened and placed into communication with said inlet means when saidpiston moves upwardly;

means interconnecting said drill head and said impactor housing; and

means for transmitting rotary motion to said drill head.

2. A boring device as set forth in claim 1 wherein said drill head has astepped lower surface for carrying said plurality of cutter bits.

3. A boring device as set forth in claim 1 including a plurality ofcutter bits carried on said stepped lower surface.

4. A boring device as set forth in claim 1 wherein a cushion pad ispositioned between said housing and said impactor.

5. A boring device as set forth in claim 1 wherein said drill head iscarried at the lower end of a drill sleeve and said impactor is withinsaid drill sleeve.

6. A boring device as set forth in claim 1 wherein the last mentionedmeans is a square Kelly.

7. A boring device as set forth in claim 1 and including means forsupplying a drilling fluid to said drill head.

8. An improved boring device for use in a borehole comprising:

a rotary drill head having a portion defining an impact pintle andadapted to carry a plurality of cutter bits;

an impactor including a fluid actuated ram positioned for impartingpercussion impacts on said impact pintle;

means interconnecting said drill head and said impactor;

a square Kelly for transmitting rotary motion to said drill head;

means for supplying a drilling fluid to said drill head, said meansincluding conduit means in said square Kelly; and

additional conduit means provided in said square Kelly for supplyingmotive fluid to said impactor.

References Cited UNITED STATES PATENTS 848,107 3/1907 Karns -418 X1,083,666 1/1914 Cook 175-415 2,033,527 3/1936 Kitching 17592 2,815,93212/1957 Wolfram 175-418 X 2,823,013 2/1958 Stenuick 1755418 X 2,873,0932/1959 Hildebrandt 175-92 3,050,033 8/1962 Carey 17592 X 3,151,68710/1964 Sato et a1. 175-95 X 3,236,318 2/1966 Burdine 175-106 NILE C.BYERS, JR., Primary Examiner.

